In recent years, electronic devices have been developed with the ability to receive and communicate control and status information to other electronic devices, and to various controller devices. For example, electric meters in residential homes may now be commanded from a controller device to transmit the electric usage status of the home to the controller device. In another example, a controller device may command an air conditioner in a home to power on, or off, in an attempt to balance the power load in a residential subdivision.
CEBus ("Consumer Electronics Bus") is a communications standard that was developed by the Electronics Industry Association's ("EIA") Consumer Group for use by such residential electrical (i.e., "consumer") devices. This standard specifies how devices are to send and receive information, the media available to them for communication purposes, and the format for the information the devices communicate to each other. In particular, the CEBus standard permits devices made by various manufacturers to be able to communicate with each other in a residential setting. The standard is documented in the CEBus EIA/IS-60 specification, which is fully incorporated herein by reference.
Thus far, networks based on the CEBus standard have been geared for "local access" control and surveillance. In particular, a specified subset of messages transmitted within a CEBus network by a controller device, or any other CEBus network device, require a CEBus "Ack" (i.e, acknowledge) message to be transmitted in response, and to be received by the device transmitting the original message within 600 .mu.secs of the transmission of that original message. Due to this stringent timing requirement, controller devices for CEBus networks have necessarily been required to be located locally, i.e., in the general vicinity of the controlled device(s), which has thus far prevented the effective extension of the CEBus standard protocol to allow for "remote access" control. The situation is further complicated if a remote controller device for exercising control of one or more devices on a CEBus network itself communicates via a non-CEBus network.
It has been proposed that remote access to CEBus automatic networks can be implemented with the use of modem links over conventional copper wire pairs. However, field trials have shown this approach to be both costly and unreliable.
Thus, it would be advantageous to provide apparatus and methods for reliable and cost efficient remote access to a CEBus network. It would be a further advantage to provide apparatus and methods for reliably mapping a CEBus network on a non-CEBus network, while still maintaining the EIA/IS-60 timing requirements.